PCR Identification of Aspergillus niger with Using Natural Additives for Controlling and Detection of Malformins and Maltoryzine Production by HPLC

Recent advances on the efficacy of essential oils on mycotoxin secretion and their mode of action

Essential oils, as extracted compounds from plants, are volatile and aromatic liquids which their unique aromatic compounds give each essential oil its distinctive essence. Fungi toxins can induce various adverse health effects like allergy, cancer, and immunosuppression. Moreover, fungal spoilage impacts pharmaceutical and food industries economic state. A drop in the utilization of synthetic compounds as food prophylaxis has occurred due to several factors such as hygiene agents' alerts and stricter legal regulations. Therefore, the applications of natural substances such as essential oils have increased in recent years. Oregano, cinnamon, thyme, rosemary, fennel, clove, palmarosa, and eucalyptus have been the highest employed essential oils against mycotoxigenic fungi and their mycotoxins in studies conducted in the past decade. Essential oils inhibit fungi growth and mycotoxin synthesis via diverse pathways including modified fungal growth rate and extended lag phase, disruption of cell permeability, disruption of the electron transport chain and manipulating gene expression patterns and metabolic processes. In the present review, we will investigate the implications and efficacy of essential oils in preventing the growth of mycotoxigenic fungi, eliminating mycotoxins and their mechanism of actions conducted in the last decade. HighlightsThe most investigated toxigenic genera are Aspergillus, Fusarium and Penicillium Spp.AB1, AG1, OTA and AB2 are the most frequently studied toxinsOregano, cinnamon and thyme are mostly exploited EOs on toxigenic fungi & mycotoxinsOregano, thyme & cinnamon are the most significant antifungals on toxigenic generaCinnamon, oregano & cinnamaldehyde are the fittest antimycotoxins on DON, OTA & AFB1.

Microwave-assisted preparation of a silver nanoparticles/N-doped carbon dots nanocomposite and its application for catalytic reduction of rhodamine B, methyl red and 4-nitrophenol dyes

In the current work, a silver nanoparticles/nitrogen-doped carbon dots (AgNPs/NCDs) nanocomposite was prepared by a microwave-assisted method that does not require additional reducing or stabilizing agents. Multiple analytical techniques were used to characterize the prepared nanocomposite. The nanocomposite exhibited a surface plasmon resonance (SPR) absorption peak at 420 nm, indicating the development of AgNPs with NCDs. Further, HRTEM results confirmed the formation of the nanocomposite with the appearance of lattice fringes of both materials. Additionally, the nanocomposite did not show any precipitation even after two months of storage. The nanocomposite exhibited high catalytic activity towards the reduction of rhodamine B (RhB, 98.83%), methyl red (MR, 97.14%) and 4-nitrophenol (4-NP, 99.95%) at ambient temperature. Besides, the kinetic analysis revealed that the reduction reaction followed pseudo-first-order kinetics and the calculated rate constants (k) for rhodamine B (RhB), methyl red (MR) and 4-nitrophenol (4-NP) were found to be 0.0296 s-1, 0.0233 s-1 and 0.029 s-1, respectively. Moreover, it is a reusable and stable catalyst for reduction reactions up to five cycles without significant loss in catalytic activity. Finally, a plausible mechanism for the reduction of pollutants is also discussed in detail. As a whole, the prepared nanocomposite might display stunning behaviour for wastewater treatment applications.

GC/MS analysis of Juniperus procera extract and its activity with silver nanoparticles against Aspergillus flavus growth and aflatoxins production

From ancient to currently, it has been hard to prevent the exposure to mycotoxigenic fungi, due to these fungi occurs naturally in the environment. This paper reports the antifungal activities of the Juniperus procera stem extract with silver nanoparticles (AgNPs) against Aspergillus flavus growth and aflatoxins production. Numerous constituents of J. procera extract were detected by GC/MS analysis. Methanolic extract at 30, 60 and 90 mg/mL inhibited the growth of A. flavus, where the inhibition reached to 50.86, 51.60 and 52.58 %. respectively while weak inhibition was observed using the aqueous extract. Growth of A. flavus was reduced using AgNPs, the highest inhibition 39.31 % was recorded at 100 ppm AgNPs. Synergistic activity was observed by applying 50 ppm of AgNPs with aqueous and methanolic extracts of J. procera . A reduction in aflatoxin B2 and G2 synthesis was observed using different concentrations of methanolic stems extract of J. procera particularly with AgNPs.

Fungal deterioration of limestone false-door monument

Unfortunately, monuments all over the world may become discolored and degraded as a result of the growth and activity of fungi. Biodeterioration is an irreversible damage that is caused by microbial colonization on the surface of buildings. Different fungi were isolated from limestone False-door in Kom Aushim museum- El-Fayoum governorate, Egypt. These include; Aspergillus niger, A. fumigatus, A. sulphureus, A. flavus, Alternaria alternata, Alternaria spp., and Cladosporium herbarium. Fungal grow on modern limestone surfaces after 60 days of infection. Transmission electron microscope demonstrated the penetration and presence of fungal threads inside limestone. Environmental Scanning electron microscope attached with EDX Unit revealed an increase in carbon and magnesium ions from 9.16 to 12.17% and 1.41–1.51%, respectively after fungal infection of limestone, while other ions decreased after infection; aluminum from 1.96 to 1.39%, silicon from 7.40 to 3.57%, potassium from 0.44 to 0.41%, calcium from 41.41 to 35.04 % and iron from 1.08 to 0.90 %. p-Chloro-m-crysol is the most potent to inhibit the growth of isolated fungi at MIC 50 ppm for most fungal species.

Safety of the fungal workhorses of industrial biotechnology: update on the mycotoxin and secondary metabolite potential of Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei

This review presents an update on the current knowledge of the secondary metabolite potential of the major fungal species used in industrial biotechnology, i.e., Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei. These species have a long history of safe use for enzyme production. Like most microorganisms that exist in a challenging environment in nature, these fungi can produce a large variety and number of secondary metabolites. Many of these compounds present several properties that make them attractive for different industrial and medical applications. A description of all known secondary metabolites produced by these species is presented here. Mycotoxins are a very limited group of secondary metabolites that can be produced by fungi and that pose health hazards in humans and other vertebrates when ingested in small amounts. Some mycotoxins are species-specific. Here, we present scientific basis for (1) the definition of mycotoxins including an update on their toxicity and (2) the clarity on misclassification of species and their mycotoxin potential reported in literature, e.g., A. oryzae has been wrongly reported as an aflatoxin producer, due to misclassification of Aspergillus flavus strains. It is therefore of paramount importance to accurately describe the mycotoxins that can potentially be produced by a fungal species that is to be used as a production organism and to ensure that production strains are not capable of producing mycotoxins during enzyme production. This review is intended as a reference paper for authorities, companies, and researchers dealing with secondary metabolite assessment, risk evaluation for food or feed enzyme production, or considerations on the use of these species as production hosts.